Rifle grenade capable of being fired by conventional ammunition



Jan; 27', 1970 H, STRECKFUSS ETAI- 3 3 RIFLE GRENADE CAPABLE OF BEING FIRED BY CONVENTIONAL AMMUNITION Filed March 8, 1968 INVENTOR Iii/MR 1/ :m e c/r n11:

3/: ran R4421- ATTORNEY United States Patent 3,491,693 RIFLE GRENADE CAPABLE OF BEING FIRED BY CONVENTIONAL AMMUNITION Heinrich Streckfuss, Dettingen, and Dieter Rall, Schramberg, Germany, assignors to Messrs. Heckler & Koch GmbH, Neckar, Pfal'llinstrasse, Germany Filed Mar. 8, 1968, Ser. No. 711,745 Int. Cl. F42b 11/42 US. Cl. 102-65.2 8 Claims ABSTRACT OF THE DISCLOSURE A rifle grenade has a tubular member which fits over the end of the rifle barrel and is intended to be fired by normal ammunition. The bullet strikes against and is collected by a member which is allowed restricted movement within the tubular member and which serves as a braking device so that the bullet is retarded without evaporation of the bullet material and enables the gas pressure to act effectively on the grenade.

The invention relates to a rifle grenade with a tubular attachment member adapted to be placed on the rifle barrel.

The known rifle grenades which are intended to be fitted over the barrel of a rifle are fired by special propellant charges which are in the form of the casing of a normal cartridge but do not include a bullet. These propellant charges must be inserted by hand into the weapon barrel after the barrel has been unloaded. The unloading and introduction of the charge is however very complicated and time-consuming with modern automatic rifles since first the magazine must be removed from the Weapon, then one must check whether a normal cartridge still remains in the barrel and then the propellant charge must be introduced into the cartridge chamber of the weapon. Also the introduction of the propellant charge into the barrel is very complicated since with such rifles the cartridge chamber is not open but the propellant charge must normally be inserted carefully into the rear end of the barrel through the ejector opening of the weapon casing. This results in the loss of valuable time which is often decisive under operational conditions. Moreover after firing the rifle grenade the rifle is not immediately ready for firing but must be loaded or cocked again for which purpose it is normally necessary to insert the magazine and to cock the weapon by hand.

A further disadvantage of the previously known rifle grenades consists in the fact that if through a mistake a normal cartridge is fired the rifle becomes unusable and moreover in this case the user runs a considerable risk of injury. Normally the bottom of the grenade which faces the barrel of the rifle comprises a base member of armour plate which prevents the bullet itself entering the rifle grenade, which might possibly cause detonation, but the impact of the bullet on the armour plate results in evaporation of the lead core of the bullet as a result of the impact energy and the lead vapours are then deposited inside the barrel. The lead layer deposited on the inside of the barrel may then result in the bullet from a subsequently fired cartridge becoming jammed in the barrel or result in distension of the barrel.

Also it may often happen that the bullet rebounds from the armour plate and breaks away from the grenade which again leads to substantial danger of damage to the operator. Since furthermore on firing a normal sharp bullet the expanding propellant gases do not act directly on the grenade but are cut off by the bullet located in the barrel of the weapon and then strike suddenly on the grenade while still at rest, the grenade does not separate 3,491,693 Patented Jan. 27, 1970 satisfactorily from the barrel and there is an excessively strong recoil. As a result of the excessive acceleration imparted to the grenade by the bullet striking on it the guide casing is often split since its mass lies behind the point of action of the accelerating forces. Moreover the hot gas products are driven out behind the weapon casing for which reason again the user is at considerable risk.

The invention is directed to the problem of avoiding the disadvantages of the known rifle grenades and to arranging these grenades so that they can be fired with normal sharp bullet cartridges. This object is attained according to the invention by the fact that the tubular attachment of the rifle grenade includes a collecting member which is displaceable in the longitudinal direction of the tube by means of the bullet of a normal cartridge striking against it and a braking device is provided in front of the collecting member.

By the arrangement of such a collecting member the bullet is not retarded suddenly but relatively slowly so that the bullet is not evaporated but by a suitable choice of the material for the collecting member it first penetrates the collecting member to some extent and then moves onward together with the collecting member until the latter comes to rest by the retarding device in the tubular part of the grenade. In this way coating of the weapon with lead from the evaporated lead core and breaking out of the bullet from the grenade are both avoided. So far as the kinetic energy of the bullet is not eliminated by the frictional or deformation effects it is transmitted to the grenade so that the latter receives an additional driving pulse. Since the collection of the bullet is effected relatively slowly as compared with the very rapid action when firing a shot, the propellant gases following the bullet act completely on the grenade and the latter is accelerated or fired in a satisfactory way. This also ensures that an excessively strong recoil is avoided and prevents the propellant gases from back-firing through the weapon casing.

The invention thus makes it possible to fire the rifle grenade with normal cartridges instead of with special propellant charges, that is with the cartridges which the user will have in the magazine so that for firing the grenade unloading of the rifle is no longer necessary so that the operator only has to insert a rifle grenade on the tube when required in order to fire it and after firing the grenade he is immediately ready for normal firing. Of course the trajectory of the rifle grenade differs from the trajectory of a normal bullet so that even when the weapon is set for continuous firing the grenade is not struck by the following shot so that there is no danger in this respect.

The collecting member can for example be supported on braking devices which are constructed in the same way as the thrust devices used in normal weapon construction and consisting for example of a packet of spring plates, of springs with braking rings or the like. Such braking devices are however relatively complicated if they are to absorb the whole impact of the bullet striking on them. For this purpose and in accordance with a further construction of the invention the collecting member i fixed in the tubular attachment in such manner that it is separated under the action of the bullet striking against it. In this way there is a substantialconsumption of energy already during the separation of the collecting member so that the braking device only has to absorb a part of the kinetic energy of the bullet.

Suitably dimensioned pins can be used for fastening the collecting member but in a preferred construction of the invention the collecting member is welded to the tubular attachment and the welding points are so dimensioned that they fracture under the action of the bullet striking against the collecting member. When automatic welding devices are used the welding points can be very accurately produced and an almost automatic production is possible so that manufacture is very cheap.

According to a further constructional embodiment the collecting member may itself embody recesses which reduce the strength of the collecting member in a crosssectional plane so that the collecting member itself fractures under the effect of the bullet striking it. Also such recesses can be easily produced by turning, drilling or the like.

A particularly simple braking device which at the same time offers a high degree of reliability and requires no resilient elements is produced in a preferred embodiment of the invention by the provision of a tapered contraction at some distance from the collecting member. The collecting member is sheared off by the impact of the bullet then runs into this tapered contraction whereby it is deformed and reliably brought to rest. As a result of the energy required for the deformation the residual kinetic energy of the collecting member is completely absorbed. In this constructional form of the invention it is particularly advantageous if the collecting member is provided with fins at its periphery which on entry of the collecting member into the tapered contraction serve as deformation members. Furthermore the tapered contraction may be provided at the end of a sleeve located in the tubular attachment and the collecting member is fastened in this sleeve.

Further details and constructions of the invention will be appreciated from the following description in conjunction with the accompanying drawing which shows a longitudinal section through the rear part of a rifle grenade constructed according to the invention.

As shown the rear end of a rifle grenade 1 is screwed to a tubular attachment 2 which carries at its rear end in known manner an aerodynamic guide element 3. The tubular attachment is intended to be placed on the barrel of a rifle and is guided in particular by the flash absorber of the weapon which is shown in chain dot lines on the drawing. At a small distance in front of the mouth flash absorber 4 a sleeve 5 is fitted into the tubular attachment 2 which embodies a tapered contraction 6 at the end nearest the grenade 1. The front end of the sleeve 5, like the tubular attachment 2, rests against a relatively rigid bottom 7 of the grenade 1.

A collecting member 8 is arranged in the cylindrical part of the sleeve 5 at a certain distance from the tapered contraction 6, which member is formed by a cylindrical block filling the cross-section of the sleeve 5. The collecting member 8 is fastened at the end face remote from the grenade 1 to the sleeve 5 by means of welding points 9 which are so dimensioned that they are severed when the bullet on a normal type of cartridge strikes on the rear end face of the collecting member 8. The collecting member 8 is furthermore provided with grooves 10 at its periphery so that fins 11 are formed which can deform relatively easily on entry of the collecting member into the tapered contraction 6. The sleeve 5 with the collecting member 8 is secured in any desired way to the tubular attachment 2 of the grenade. It is suflicient to press the sleeve into the tube since the sleeve is supported at its end face on the bottom 7 of the grenade and hence the tubular attachment 2 does not have to absorb the forces applied to the sleeve when the grenade is being fired.

The grenade shown in the drawing is suitable and intended to be fired with normal rifle ammunition. When the bullet of a normal cartridge strikes the rear face of the collecting member 8 the welding points 9 are severed under the action of the impact so that the collecting member 8 can move in the sleeve 5 in the direction towards the grenade 1. So much energy is absorbed by the severance of the collecting member 8 that insuflicient energy is left for evaporating the lead core of the bullet. Moreover the collecting member 8 can be formed of relative y soft mater a or e a p f om. normal mild steel, so that the impact of the bullet on the collecting member 8 is not so hard as the impact on the armour plate material previously used in rifle grenades. Furthermore the bullet can penetrate into the collecting member.

After separation the collecting member 8 with the bullet embedded in it moves in the direction of the tapered contraction 6 in the sleeve 5. On entering the tapered contraction the foremost fin 11 of the collecting member is deformed. This deformation absorbs energy so that the collecting member is reliably brought to a standstill in the tapered contraction 6, if necessary with the deformation of further fins 11. These actions proceed at a speed which is of the same order of magnitude as the other actions occurring on firing a shot so that the pressure of the propellant gases can build up completely in the tubular attachment 2 of the grenade and hence the grenade is fired from the barrel of the weapon just in the same way as with the usual propellant charges. Moreover by the relatively slow retardation of the bullet a part of the kinetic energy of the bullet is transferred to the grenade. Furthermore any disadvantageous effects on the operator are reliably avoided when using the invention.

It should be understood that the invention is not limited to the construction example shown but that variations may be included without departing from the scope of the invention. Other types of fastening and other constructions of the collecting member may be adopted and also other arrangements of braking or retarding devices and in constructional forms of the invention only some of the features specified above may be used singly or in any combination. The constructional example shown is of particularly simple construction, can be produced cheaply and provides a very high degree of functional safety.

What is claimed is:

1. A rifle grenade, comprising body means containing the grenade charge, tubular means securely attached, at one end thereof, to said body means, the opposite end being adapted to be placed over the barrel of a rifle, collecting means shearably secured within and contacting said tubular means and displaceable in the longitudinal direction thereof under the impact of a bullet fired from the rifle, and braking means, disposed within said tubular means in advance of said collecting means and secured therewithin for motion together therewith upon displacement of said collecting means into engagement with said braking means.

2. A rifle grenade according to claim 1, wherein said collecting means is spot welded within said tubular means, the weld points being so proportioned as to fracture under the action of a bullet striking said collecting means.

3. A rifle grenade according to claim 1, wherein said collecting means includes zones of reduced strength in cross-sectional planes, thus causing a deformation thereof under the impact of a bullet.

4. A rifle grenade according to claim 1, wherein said braking means includes a tapering constriction.

5. A rifle grenade according to claim 4, wherein said collecting means is dimensioned so as to permit entry thereof into said tapered constriction under impact of a bullet and is provided with fins about the periphery thereof which serve as deformation members on entry of said collecting means into said tapered constriction.

6. A rifle grenade according to claim 5, wherein said tapered constriction is located at an end of a sleeve disposed within said tubular means, said collecting means being initially secured to said sleeve.

7. A rifle grenade according to claim 1, wherein said collecting means is formed from a relatively-deformable material, thus permitting a bullet striking said collecting means to penetrate same.

8. A rifle grenade according to claim 7, wherein said collecting means is formed from mild steel.

(References on following page) References Cited UNITED STATES PATENTS 478,020 6/1892 Pollard 89--14 1,900,790 3/1933 Brandt 421.2 5 2,853,008 9/1958 Bowles 102-652 6 FOREIGN PATENTS 604,510 5/1926 France. 591,485 4/1959 Italy.

BENJAMIN A. BORCI-IELT, Primary Examiner JAMES FOX, Assistant Examiner UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,491 ,693 January 27 1970 Heinrich Streckfuss et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, lines 5 and 6, "assignors to Messrs Heckler G Koch GmbH, Neckar, Pfafflinstras:

Germany" should read assignors to Messrs. Heckler G Koch GmbH, Oberndorf (Neckar) Germany Signed and sealed this 4th day of August 1970.

' (SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, J r.

Commissioner of Patents Attesting Officer 

